Part-Load Enrichment Diaphragm Solex 32 PBISA carburetors as used on, amongst others, the Citroen Visa 1100 and Peugeot 205.
These diaphragms now tend to suffer from age and the ravages of aggressive modern fuels which causes the "rubberized textile" material to harden and even crack, causing erratic running of the engine and fuel leaks.
Replacing the diaphragm is then the only sensible option.
Please note that not every Solex PBISA is equipped with this diaphragm.
Required quantity per carburetor: 1
This is item 25 in the drawing.